1. Field of the Invention
The present invention relates to a method of creating a data base for use in a hypertext system.
2. Description of the Related Art
In a data base used in a hypertext system, nodes are provided which represent units of data and links are provided between corresponding nodes.
For example, if a dictionary is used as a data base, a link is present between a node which represents an antonym and a node which represents a synonym. The links represent items of the dictionary relating to a certain entry, and mutual reference between the nodes is possible.
A conventional data base used in the hypertext system is created by one of the following two methods.
(1) The user creates data serving as nodes for each unit of data and sets each link one by one depending on the relationship between the created nodes.
(2) The user creates one datum corresponding to each node, directs the hypertext creation of the created datum, and thereby achieves the division of the datum into nodes and the creation of links between the divided nodes.
Method (1) is disclosed in, for example, "Intermedia: The Concept and the Construction of a Seamless Information Environment", Yankelovich, N. et al., IEEE Computer, Jan. 1988, pp. 81-96.
In method (2), an ordinary document is analyzed and divided into the title, the name of the author, chapter headings, sentences in each chapter and each paragraph, drawings and so on, each of which is used as a node. The paragraphs in a chapter are linked to the heading of the chapter, or the hierarchic structure. The body of the document (i.e. chapters and paragraphs) is extracted and the body of the document, the title, the name of the author and so on are linked to one another. Furthermore, a portion of a certain paragraph where a certain drawing is referred to, for example, a phrase "in FIG. 1" is detected and the paragraph and FIG. 1 are linked, or the relation between two paragraphs is determined based on a conjunction at the beginning of the latter paragraph and the paragraphs are linked if there is some relation between them.
Although nodes and links can be created as the creator of the hypertext intends in method (1), an enormous amount of labor and time are required by the creator.
On the other hand, although method (2) eases the burden on the creator, if the creation process is incorrect, it is necessary to correct the created hypertext. In particular, if there is an error in the creation process of the nodes, it is necessary to correct erroneous nodes and to add and delete links relative to the nodes. Thus, much labor and time are needed for the correction.